Through Hole Resistors

Through-Hole Resistors, also known as axial-lead resistors, are electronic components that limit or regulate the flow of electrical current in a circuit. They are characterized by having two leads protruding from the body of the resistor, which are inserted through holes in a printed circuit board (PCB) and soldered to pads on the board's surface.

Definition:
A through-hole resistor is a passive electronic component designed to resist the flow of electrical current. It is made up of a resistive material, typically a ceramic or carbon composition, coated with a protective layer and encased in a plastic or glass tube.

Function:
The primary function of a through-hole resistor is to control the amount of current that passes through a circuit. This is achieved by converting electrical energy into heat, which is dissipated. Resistors are used for various purposes, including:
1. Voltage division in voltage divider circuits.
2. Current limiting to protect sensitive components.
3. Pull-up/pull-down resistors in digital circuits to ensure a defined logic level.
4. Termination of transmission lines to reduce signal reflection.

Applications:
Through-hole resistors are used in a wide range of applications due to their robustness and ease of handling. They are found in:
1. Audio and video equipment for signal processing and level control.
2. Power supplies for voltage regulation and current limiting.
3. Industrial control systems for motor control and sensor circuitry.
4. Consumer electronics for general circuit design and protection.

Selection Criteria:
When selecting a through-hole resistor, several factors should be considered:
1. Resistance Value: The resistor's value must be appropriate for the circuit's requirements.
2. Tolerance: This is the allowable deviation from the stated resistance value, typically expressed as a percentage.
3. Power Rating: The resistor must be able to handle the power dissipation required by the circuit without overheating or failing.
4. Size: The physical dimensions must fit within the constraints of the PCB layout.
5. Temperature Coefficient: The change in resistance with temperature should be considered for precision applications.
6. Lead Material: The material of the leads can affect the solderability and mechanical strength of the connection.
7. Cost: The budget for the project may influence the choice between standard and precision resistors.

In summary, through-hole resistors are versatile components that play a crucial role in controlling electrical current in various electronic circuits. Their selection should be based on the specific requirements of the application, including resistance value, tolerance, power rating, and physical dimensions.
Please refer to the product rule book for details.